1. Field of the Invention
The present invention relates to a video camera system in which both a camera body and an optical accessory have connecting terminals for electrical connections, or an optical accessory.
2. Related Background Art
Conventionally, in multiple-plate type video cameras using color separation prisms, a lens exchangeable video camera system which allows optical accessories or accessories such as exchangeable lenses, various kinds of converters, and the like to be freely attached/detached by adopting a bayonet mount, is known.
In such video camera system, an electrical connection is normally attained outside a mount using a cable and connectors attached to the ends of the cable as power supply or communication means from a camera body to an optical accessory. In recent years, another type of mount has been proposed. With this mount, electrical connecting terminals are arranged on flange portions of mounts of the camera body and the optical accessory, and an electrical connection between the two mounts can be attained simultaneously with the mechanical mounting of them.
However, in the prior art, since the electrical connecting terminal is disposed on the flange portion of each mount, the width of the flange portion must be increased, resulting in a mount with a large outer diameter and a large weight.
On the other hand, the mount and its flange portion consist of a hard metal for the purpose of suppressing wear as much as possible. For this reason, a machining process for arranging the electrical connecting terminal on such portion requires high cost.
Furthermore, since a user can relatively easily touch the contacts of the electrical connecting terminal arranged on the flange portion of the mount when the optical accessory is detached from the camera body, a short-circuiting accident between terminals due to a metal piece such as a coin, a contact error due to dust, or the like readily occurs.
A multiple-plate type video camera tends to have a long back focus since a color separation prism must be disposed. When the electrical connecting terminal is arranged on such camera, the back focus is further prolonged, resulting in a large, heavy camera.